First of all, to answer you, this dream has no warning. Secondly, you have this dream for three reasons. First, you have deep feelings for grandma, and grandma is very kind to you. Secondly, you dream of grandma riding a bike because you always think that grandma can live a healthy life and exercise during the day, but when you see grandma riding a bike in your dream, you will think of grandma's old problems, so you will naturally think of grandma's illness during the day (breathing will be accelerated during exercise). Finally, I still want to tell you that dreams are dreams after all. I wish grandma health and happiness every day!
My grandmother has a heart attack, too. You can ask the doctor if you can take Danshen tablets for a heart disease like grandma's. Danshen tablets belong to traditional Chinese medicine and can be taken every day. Mild heart disease can be very effective.